Banging Noise From Pipework

A banging noise in pipes is commonly caused by water hammer, which occurs when a valve closes suddenly, creating a pressure surge that causes pipes to vibrate or "hammer". Other causes include loose pipes, which can vibrate and knock against walls, and thermal expansion of hot water pipes. High water pressure can also make pipes bang. 

• Water Hammer: This is the most common cause, happening when the flow of water is stopped abruptly by appliances like washing machines, dishwashers, or toilets. The sudden stop creates a shockwave that causes the banging noise.

• Loose Pipes: If pipes are not securely fastened to the wall or joists, they can move and bang against surrounding materials as water flows through them.

• High Water Pressure: If your home's water pressure is too high (over 80 PSI), it can create enough force to make pipes shake and knock.

• Thermal Expansion: Hot water pipes can expand when hot water flows through them and then contract when the water cools. This expansion and contraction can cause them to knock or "ping" against framing or other pipes. 

• Address Water Hammer (air chambers):

  • Turn off the main water supply to your house.

  • Open all the faucets in your home to drain any remaining water.

  • Turn the main water supply back on.

  • Turn off all the faucets. This should re-establish the air cushion that prevents water hammer.

• Secure Loose Pipes:

  • Examine exposed pipes and tighten any loose straps or clips that are holding them in place.

  • If you can't reach the pipes, a plumber may be needed.

• Reduce High Water Pressure:

  • Use a water pressure gauge to check your home's water pressure at an outdoor spigot.

  • If the pressure is consistently above 80 PSI, you may need to have a pressure-reducing valve (PRV) adjusted or replaced by a professional.

• Consider a Water Hammer Arrestor:

  • If DIY fixes don't work, you can have a professional install a water hammer arrestor, which is a device designed to absorb the shock of water hammer, particularly near problem appliances like washing machines.